Figure 1. The course of paresthesia. Above the time axis is the paresthesia symptom course: the thickest line means the severest symptom, the median line means symptom decreasing in intensity, and the thinnest and dotted line means symptom even decreasing in intensity and frequency. Under the time axis is the levothyroxine treatment course: the linear box filled with black means dosage of 0.1 mg/day and the linear box with arrow filled with gray means dosage of 0.05 mg/day. Under the levothyroxine treatment course is the duloxetine treatment course: the dosage was fixed at 60 mg/day throughout the course. The patient continued with both two medications. The double oblique lines means that some time elapsed were omitted to focus on important events of this patient. T3, triiodothyronine; T4, thyroxine; fT4, free thyroxine; TSH, thyroid-stimulating hormone; VAS, visual analog scale; y/o, years old.